The English flora - SeaweedAfrica

374 ALGM CONFER VOIDED. [Oscillatoria.
" The irregularity of its appearance arises from the filaments being collected
together into little- ascending tufts, apparently rooted in the muddy
deposit of the water. Each tuft proves, on examination, to consist of
simple, uniform, even filaments, crowded together and quite pellucid
and equally destitute ofjoints and branches ; their diameter is not more
than an eight or ten-thousandth part of an inch." Sm.
** Virescentes. Stratum of an ceruginose or blue-green colour.
5. O. limosa, Ag. (green Mud Oscillatoria); stratum rich
dark-green glossy gelatinous with long rays, filaments green
thick straight and rigid, striae strongly marked and very closely
set Ag. Syst. Alg. p. 66. (not of Grev. Fl. Edin. p. 303,
nor Hook. Scot. P. II. p. 79 )
Ditches and pools.— Stratum of very rapid growth and intensely
rich dark-green colour, sending out long radii, equally or in bundles,
of scarcely a paler hue than the stratum. Filaments thicker than in
any other British species, bluish-green (under the microscope) vividly
oscillating.— This fine species is apparently alluded toby Dilhvyn, in his
description of Conferva fontinalis, t. 6 i ; but the figure is more like O.
nigra. In drying, it adheres closely to paper. From O. major, it differs
in the much greater diameter of its filaments, and darker colour; and
from O.jirinceps (apparently), in the smaller size and brighter colour. It
is therefore intermediate between these species.
6. O. tenuis, Ag. (lesser Mud Oscillatoria); stratum rich darkgreen
very thin gelatinous with short rays, filaments pale-green
straight and rigid, striae distant not strongly marked. Ag. Syst.
Alg. p. 65. Grev. Fl. Edin. p. 303 O. limosa, Hook. Scot.
P. II. p. 79.— Conferva limosa, Dillw. Conf. t. 20.— O. viridis,
Johnst. Berw. Fl. p. 264.
In muddy ditches, at first resting on the bottom ; but gradually ris-
ing in bullated strata to the surface; common— Stratum extensive, glossy
when dry, in which state it fully preserves its colour. Filaments^ half
the diameter of those of O. limosa, pale-green ; striae distant and indistinct.
It adheres strongly to paper.
7. O. cydnea, Ag. (bluish Oscillatoria); glaucous-blue, filaments
simple entangled cylindrical even with a deciduous coat,
joints obsolete about as broad as long. Sm.—Ag. Syst. Alg.
p. 68. E. Bot. t. 2578.
Damp walls on the inside of several Suffolk churches, as Icklingharn
and Hengrave ; also in Lancashire, Sir Thomas Gage, Bart.—" On the
wall it is conspicuous for its light sky-blue colour, like some sort of
Mucor. Under a high magnifier, and when moistened, it is found to
consist of minute, even, simple, entangled threads, one 500dth part of
an inch in diameter, coated with a frequently interrupted covering, of a
dull glaucous-green hue, under which the thread itself appears of a
lighter glaucous-bluish colour, very even in thickness and surface, consisting
of scarcely distinguishable joints, about as broad as they are long."
Sm.
8. O. splendida, Grev. (bright-green Oscillatoria); stratum
bright seruginose or blue-green thin with short rays, filaments
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